Clinicians working in rehabilitation settings have a need to easily quantify their patients' gait parameters in order to objectively document effectiveness of therapeutic interventions. Historically, however, no equipment has been readily available for them to do so easily. Instead, gait measurement devices have historically come in three variations. One version uses external video capture with markers on the user to identify the real-time location and movement of specific locations on the user. Gait parameters can be extrapolated based upon the location and movement of these markers. This approach requires significant costs for the associated hardware and software. It also requires excessive set up and calibration time to properly place each camera in a location that captures the data appropriately. It also requires a fairly large portion of the room to be dedicated to the video capture system. The comprehensive data provided by these systems is sophisticated and detailed enough to be used for research purposes, and is more than that needed for a typical clinician.
A second version uses multiple force sensors embedded across the entire treadmill deck to sense the vertical force, or load, on the deck. Force sensors are expensive and an array of them is geometrically more expensive. And, although an array of multiple sensors may provide more precise gait measurements, the calculations become increasingly more computationally expensive with more sensors because there is much more data to analyze and more (or more powerful) processors are required. As with the video capture systems, these systems provide more data than would be needed for a typical treating clinician. These systems also require significant modifications to the treadmill to allow for the installation of the instrumented deck.
A third version uses one or more force plates positioned directly below the treadmill belt which sit atop force sensors to sense the load on the treadmill belt as it is transferred to the force plates. Force plate construction is somewhat disadvantageous in that it causes uncertainty in the gait measurements because of friction and vibration between the belt and the force plates. Friction is notoriously difficult to compensate for in gait calculations, due in part to its variability and multi-dimensional effects. In addition, as with the instrumented deck version, significant modifications are needed to implement this type of gait measuring system on an existing treadmill.
Treating therapists typically do not have time to set up a complicated gait recording system, nor can they spend significant money to do so. They also do not need a system that provides an abundance of data—just a few simple parameters that can be compared over time to assess a patient's gait and progress. Given that treadmills are common equipment for rehabilitation clinicians, it would be advantageous to use clinicians' treadmills to measure gait parameters.
Therefore, it is an object of this invention to provide a relatively low cost, simple gait-recording system that provides appropriate gait parameters that can be used daily in the clinic. It is another object to provide a gait measurement system that can be easily retrofitted to a therapist's existing treadmill.